Electronic cash registers are conventionally employed to register and process sales information, to enable more rapid and effective treatment of sales data. Referring to FIG. 1, a conventional electronic cash register 10 is generally comprised of a terminal 11, which in its simplest form may be a repackaged personal computer. The cash register includes a keyboard 12 for entering sales or other pertinent data, as well as a display 13 for displaying any desired information that has been processed by the terminal. It is of course apparent that other I/0 devices, such as a printer (not shown) for providing a hard copy of sales data, is preferably also provided in such a system.
It is frequently desired to enable input of data to the terminal from other sources, such as a bar code reader, a magnetic stripe reader, a laser gun, an optical character reader, etc. For this purpose, a decoder interface 14, known as a "wedge", may be connected to the terminal via the keyboard port of the terminal. In such an arrangement, the keyboard 12 is connected to the terminal via the wedge 14, as illustrated in FIG. 1, rather than directly to the terminal. The term "wedge", in its specific sense, refers to the injection of data in the keyboard connection. The term "decoder" is a generic term that refers more generally to the decoding of signals resulting from the scanning of bar codes, including keyboard wedges or other connections such as the OCIA port on NCR electronic check readers. These two terms will be used interchangeably in the present disclosure, however, since they are used interchangeably in the industry. The wedge is adapted to be connected to one or more external input devices 15 for conversion of the output of the external device to a form that can be employed by the terminal. In this arrangement, the wedge 14 combines the outputs from the keyboard and from the external device(s), and sends the composite output signal to the electronic cash register terminal. The terminal cannot tell the difference between signals received from the keyboard, and signals received from the external device.
A typical wedge of this type is the Scanteam 2100 or 2120 decoder manufactured by Welch Allyn of Skaneateles Falls, N.Y. 13153, which is provided with a port for interfacing a wand or laser scanner, a port for interfacing magnetic slot readers, and an optional RS232 port. In addition, this device has an internal program enabling it to be configured to a particular application, in a setup procedure, to convert known outputs from an external device to desired codes for application to the terminal. Model 350 and 385 wedges manufactured by Symbol Technology Co. of Bohemia N.Y. are similar types of wedges.
While a wedge of this type is suitable for interfacing external devices for which it was designed, its universal adaptability to interface a number of different types of external devices necessarily increases its complexity and price. Such an increased price may not be cost effective in some point of sale operations, where universality of application is not required.
For example, as illustrated in FIG. 2, the wedge 14' may be provided with an MSR input port for receiving signals from a magnetic stripe reader 16, a scanner port for receiving signals from a scanner 17, and an auxiliary port for receiving RS232 signals from a check reader 18, such as the CR-1 check reader produced by the assignee of the present application. In this arrangement, the inclusion of the RS232 auxiliary port on the wedge adds extra cost to the wedge. In the event that the user had previously employed a wedge that did not have an RS232 port, the addition of the check reader 18 to the system may require the user to obtain a completely new wedge, since retrofitting of the presently available wedge may not be possible.
In order to avoid a requirement to obtain a new universal wedge, the user may have the alternative, as illustrated in FIG. 3, of still employing the previous wedge 14", without the additional auxiliary port, and instead purchasing a wedge 19 that is provided with an RS232 port. This output of this additional wedge is connected, as illustrated, in series with the outputs of the keyboard and the existing wedge 14'. While this solution may be less costly than that of FIG. 2, it still requires the user to purchase an additional wedge. It must be stressed that designing a wedge is a quite complex process, and hence the designing of a wedge adaptable to all terminals, keyboards and devices may not be economically feasible.
In an alternative arrangement for interfacing an external device 15 to the terminal 11, as illustrated in FIG. 4, the interface may be comprised of a decoder 20 adapted to be connected directly to a port 21 of the terminal, other than the keyboard port. In this arrangement, the interconnection between the keyboard and terminal is not modified. The decoder 20 combines the outputs from one or more external devices 15, and sends the composite signal to the special input port of the terminal. This arrangement also enables the terminal to send data and control signals to the decoder. The arrangement has the disadvantage, however, that a special port is required on the terminal. With this arrangement it is still necessary to buy a decoder, and the decoder may not be adapted for RS232 input. In such cases it may thus be necessary to install hardware with an additional port for the electronic check reader, and to purchase an additional wedge. This results in increased costs to the user, and inhibits the user from employing lower cost unmodified conventional terminals.